Plantar flexor neuromuscular adjustments following match‐play football in hot and cool conditions

Abstract

We assessed neuromuscular fatigue and recovery of the plantar flexors after playing football with or without severe heat stress. Neuromuscular characteristics of the plantar flexors were assessed in 17 male players at baseline and ∼30 min, 24, and 48 h after two 90-min football matches in temperate (∼20°C and 55% rH) and hot (∼43°C and 20% rH) environments. Measurements included maximal voluntary strength, muscle activation, twitch contractile properties, and rate of torque development and soleus EMG (i.e., root mean square activity) rise from 0 to 30, −50, −100, and −200 ms during maximal isometric contractions for plantar flexors. Voluntary activation and peak twitch torque were equally reduced (−1.5% and −16.5%, respectively; P < 0.05) post-matches relative to baseline in both conditions, the latter persisting for at least 48 h, whereas strength losses (∼5%) were not significant. Absolute explosive force production declined (P < 0.05) 30 ms after contraction onset independently of condition, with no change at any other epochs. Globally, normalized rate of force development and soleus EMG activity rise values remained unchanged. In football, match-induced alterations in maximal and rapid torque production capacities of the plantar flexors are moderate and do not differ after competing in temperate and hot environments.

The assessment of neuromuscular fatigue during 120 min of simulated soccer exercise

“…Following 90 min of match-play reductions in VA of <2% (Girard et al 2015;Nybo et al 2013) and ~8% (Rampinini et al 2011) have been previously reported which is less than observed in this study (~16%, Fig. 2c).…”

“…Soccer match-play also results in significant central fatigue; a reduced VA of the knee-extensors (~ 8%) following 90 min of football matchplay was first reported by Rampinini et al (2011). Smaller reductions of ~ 1.5% in VA of the plantar flexors have also been reported following 90 min matches in hot (43 °C) and temperate (~ 20 to 21 °C) environments (Girard et al 2015;Nybo et al 2013). However, in these investigations, the post-match fatigue assessments were recorded 30-40 min following the match, a time in which the degree of fatigue would have dissipated.…”

“…Fatigue in soccer has been the subject of several reviews (Bangsbo et al 2007;Mohr et al 2005;Nedelec et al 2012) and experimental study (Andersson et al 2008;Oliver et al 2008;Rahnama et al 2006;Robineau et al 2012), however, a limited number of investigations have attempted to quantify the neuromuscular fatigue response, with equivocal results (Girard et al 2015;Marshall et al 2014;Nybo et al 2013;Rampinini et al 2011). Fatigue is classically defined as an exercise-induced reduction in the ability of a muscle or muscle group to generate maximal force (Gandevia 2001), which stems from peripheral and central mechanisms.…”

“…Peripheral fatigue is the loss in muscle force caused by disturbances in sites at or distal to the neuromuscular junction, whereas central fatigue is defined as a progressive, exercised-induced reduction in the voluntary activation (VA) of muscle (Gandevia 2001). Simulated and actual soccer match-play has been shown to elicit substantial peripheral fatigue (Clarke et al 2015;Girard et al 2015;Rampinini et al 2011) likely attributable to alterations in excitation-contraction coupling. Soccer match-play also results in significant central fatigue; a reduced VA of the knee-extensors (~ 8%) following 90 min of football matchplay was first reported by Rampinini et al (2011).…”

Futsal Match-Related Fatigue Affects Running Performance and Neuromuscular Parameters but Not Finishing Kick Speed or Accuracy

“…The uncoupling between VA and RMS responses might be a result of the characteristic of the measures, since VA is the sum of the responses of all the knee extensor muscles to the superimposed motor nerve stimulation, while the EMG is a muscle-specific index (Girard et al, 2015b). Furthermore, it is possible that the load sharing strategies of quadriceps femoris could be altered under fatigue and contribute to maintenance of the RMS value of the vastus lateralis muscle after the simulated game (Bouillard et al, 2014).…”